Retractable utility knife



FIG. 1 is a perspective view of a retractable utility knife showing the blade thereof in an extended position.

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a left side elevation view thereof;

FIG. 5 is a right side elevation view thereof;

FIG. 6 a rear elevation view thereof; and,

FIG. 7 is a front elevation view thereof.

The broken line showing of the blade is included for the purpose of illustrating environmental structure and forms no part of the claimed design. 

The ornamental design for a retractable utility knife, as shown and described. 